Marker ejector



May 15, 1962 o, c. NIEDERER MARKER EJECTOR 4 Sheets-Sheet 1 Filed Aug. 31, 1960 IN VEN TOR. OTTO CHR S TOPHER NIEDERER.

y 1962 o. c. NIEDERER 3,034,227

MARKER EJECTOR Filed Aug. 51, 1960 4 Sheets-Sheet 2 IQ b a:

I Q II 1 N I co m INVENTOR. OTTO CHRISTOPHER IVIEDEREB M/MA 0 C. NIEDERER MARKER EJECTOR May 15, 1962 Filed Aug. 31', 1960 4 Sheets-Sheet 3 R NR m k W m m T J mm 2 w XX x x \vhfi 1 L J L a W Kr mm mm. wm 8 mm 3 fi Q g \k aw v mm .x. 8 on OTTO CHIC I STOPHEB N IEDEBER 4 Sheets-Sheet 4 INVENTOR.

BY J OQ J May 15, 1962 o. c. NIEDERER MARKER EJECTOR Filed Aug. 31, 1960 NGQQIO Ibmwn o'rTo CHRISTOPHER. mans/e52 United States Patent MARKER EJECTOR Otto C. Niederer, Westfield, N.J., assignor, by mesne assignments, to the 'United States of America as represented by the Secretary of the Navy Filed Aug. 31, 1960, Ser. No. 53,325 3 Claims. (Cl. 35--10.2)

This invention relates to a novel marker for submerged articles and more particularly although not exclusively for simulating the explosion of submerged submarines.

This invention is used in conjunction with a depth charge amplifier, electronic package and submarine simulator, respectively in patent applications, Serial Nos. 84,467 filed Jan. 23, 1961 and 38,683 filed June 24, 1960 which are assigned to the US. Government as represented by the Secretary of the Navy. In order to simulate the hit of a depth charge upon a submarine simulator or decoy for either training or decoy purposes, operable underwater craft and underwater simulators utilize marker ejectors for ejecting miscellaneous apparatus. The instant invention provides a novel device for ejecting markers comprising either yellow buoyant disks or oil for simulating an oil slick, or. a buoyant dye cartridge which rises to the surface and allows the dye to diffuse. Ejection of these materials occurs when a depth charge is dropped sufiiciently close to the underwater craft to be considered within the homing range of an acoustic torpedo.

It is a general object of the present invention to provide an improved marker ejector for realistically simulating the debris associated with a direct depth charge hit upon an underwater craft.

It is a further object of this invention to provide an improved marker ejector assembly which maintains the hull of an underwater craft watertight before and after marker ejection.

It is another object of this invention to provide a marker ejector assembly for underwater craft which permits automatic ejection of any one of four diiferent markers.

A further object or" the invention is to provide an improved marker ejector of the class described which is positive in operation, relatively simple in construction, easy to manufacture, and otherwise well adapted for the purposes described.

Another object of the instant invention is to provide a marker ejector assembly for automatic operation on unmanned underwater craft.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 shows the marker ejector assembly with one breech disassembled;

FIG. 2 shows the details of the squib holder for each breech;

FIG. 3 shows an alternate design in which the breech and barrel are made in one piece;

FIG. 4 shows the details of the packing gland;

FIG. 5 shows the details of the packing retainer disc;

FIG. 6 shows the details of the packing retainer ring;

FIG. 7 shows a section taken along 7-7 of FIG- URE 1;

FIG. 8 shows a marker retainer; and

FIG. 9 is a schematic diagram of the marker bomb circuit.

Referring in particular to FIG. 1, the hull member section It) has four holes drilled around its external arcuate section, these barrel holes being respectively 12., 14, 16 and 18. Associated with each barrel hole is a Patented May 15, 1962 breech which is mounted on the inside of the marker assembly, respectively 20, 22, 24 and 26. The squib holder is shown disassembled at 28 of FIG. 1. It comprises a rubber packing gland 30, a nylon washer 32 and a brass retainer disc 34 and a packing retainer ring 29 to seal the device against seawater once the buoyant marker disks 36 have been ejected. The squib holder 28 is shown in detail in FIG. 2. The squib holder in the preferred embodiment is made of brass and threaded at both ends 38 and 40. 'Two holes 42 and 44 are drilled through the squib holder for the explosive charge. An inset at the other end of the breech 46 provides a space for the packing gland 30 which seals the inside of the hull member 0E from the external fluid after the markers have been ejected and provides paths for the electrical Wires connected to the squibs which are located in each of the holes 42 and 4d. The gland 30 has four holes 81, 82, 83, and =84, one for each of the wires coming from the squibs. As shown in FIG. 4 theholes 81 and 82 start at a common point and diverge so that each solid wire of the squib is held with no chance of water leakage. In a similar manner and for the same reason, holes 83 and 84 start at a common point 86 and also diverge. The packing gland 30 is compressed and held in place by the packing retainer disc 34, said disc having'four wire clearance holes 87, 88, 89, and 90 which line up with the holes 81, 82, *83, and 84 of the packing gland 30. Clamp section 29 screws onto the threaded end 40 (FIG. 2) for retaining the packing gland retainer disc 34. Each squib holder 28 (FIG. 2) has external threads 38 which screw into the appropriate hole 91 in the marker assembly (FIG. 7). Leakage through the threads is prevented by a nylon washer 32 (FIG. 1) which fits over the threads 38 and is compressed between the hull section 10 and the flange 54 (FIG. 2) on the squib holder 28. The marker assembly in the preferred embodiment is made of aluminum. The buoyant marker discs 36 are retained in the barrel 92 by the marker retainer 93 which is made of water proof flexible material and inserted into the barrel groove 94 and sealed by use of sealing wax or other suitable material.

FIG. 3 shows an alternate design in which the squib holder and barrel are made in an integral unit and screwed into any hull section by means of the threads 48.

The marker bomb circuit for firing the squib and dispensing the marker is shown in FIG. 9. It comprises a relay 56 and a stepping relay 5% which operates as a function of the incoming signal which denotes the proximity of a depth charge. The 24 volts for operating the marker bomb circuits is available only after a start switch and a dynamotor relay contacts are closed, thus providing breaks in the circuit for safety purposes.

The sonic signal is received by the sonic transducer and is amplified by the depth charge amplifier shown in FIG. 9. This amplifier comprises a tuned amplifier stage and detector 62, and a DC. amplifier 64 terminated in a relay 66. Noise signals from the transducer are applied to the grid of the tuned stage. The center frequency of this stage in the preferred embodiment is 29 kc. The band width is approximately 1 kc. The output of the tuned circuit is rectified by the detector stage and amplified by stage 64. When no signal is present, the plate current of stage 64 is sufiicient to operate the relay. When a signal is present, the stage 64 becomes cut off and the relay 66 actuates relay 56 which in turn actuates the stepping relay 58 which advances the contacts one position and applies positive voltage to the marker squibs in sequence.

For initial setup the stepping switch in the detonator section must be set two steps from the first firing point. This is because the relay 66 will be in non-operating condition when power is first applied until the D.C. amplifier stage 64 warms up.

Signal is coupled to the depth charge sensing amplifier from the echo elongator circuits in the preferred embodiment. The electronic parts ofv the amplifier circuit are those normally associated with an amplifier of this kind and will not further be discussed. In operation, when a noise signal is received by the noise transducer with said noise signal being of sufiicient amplitude and frequency, a signal is applied to the grid of depth charge sensing amplifier 62. This signal must be of sufficient magnitude to cut off the D.C. amplifier stage 64 thereby initiating the marker ejections by causing relay 58 to step in sequence. As relay 58 steps, +24 volts is applied through the wires going through the packing gland 30 thereby applying voltage to the explosive charge withintthe squib holder 28 and causing the appropriate barrel to fire. When the noise signal ends, the D.C. amplifier stage 64 is no longer cut off, relay 66 thereupon is actuated causing relay 56 to drop open thereby removing the positive voltage from the contacts of the stepping relay, thereby eliminating a seawater short circuit in the squib holder which is now empty, the squib having disintegrated and the marker retainer 93 and the marker discs 36 having been expelled by the explosion. The marker assembly may be packed with any one of a number of diiferent markers such as dye, oil, disks or any other visible type of marker to simulate submarine detonation.

Obviously many modifications and variations of the s 4 7 present invention are possible in the light of the above teachings. It is therefore to, be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. A marker ejector for use in an underwater craft comprising a watertight hull section adapted to be mounted on said underwater craft and barrel members each containing a marker, said barrel members being mounted within said hull section and adapted to project said markers, and a squib positioned underneath each said marker in each said barrel member for ejection thereof, a firing means, said squib being operatively connected to said firing means, said firing means being arranged to operate automatically upon the proximity of a noise signal.

2. The combination of claim 1 wherein said barrel means comprise a marker disk dispenser and sealing means for said disks.

3. The combination of claim 2 wherein said automatic firing means for said squib comprises a stepping relay and a source of DC; voltage.

References Cited in the file of this patent UNITED STATES PATENTS 2,710,458 Reed June 14, 1955 2,832,265 Reid et al. Apr. 29, 1958 2,938,483 Mason May 31, 1960 

